Answer the following questions (Work in pairs)

Notes on the Text

1.it should be noted – необходимо отметить

2.to account for – объяснять

3.mass-produced materials – изделия массового производства

1. What was the very first solid material that man began to use? 2. What did natural ceramics provide man with? 3. Why was ceramics used in a variety of applications? 4. Why did man get interested in ceramics so much? 5. What is ceramics? 6. What is a main characteristic of the construction of ceramic crystals? 7. Why are the ceramic materials so strongly resistant? 8. What are the principal elements in natural clays? 9. What does the construction of ceramic materials depend on? 10. Why are ceramic materials mass-produced? 11. Why is the ceramic industry so important?

13. Open the brackets using the correct verb form:

Last year our plant (produced, produces) many ceramic goods which (are used, were used) widely. 2. At first man (baked, has baked) vessels of clay in the sun. 3. Recently ceramic compounds (are used, have been used) even in making steel. 4. Numerous analyses (have been carried out, had been carried out) before they stated the exact composition of this compound. 5. Now many scientists (are working, work) at the investigation of the new properties of ceramics. 6. Many new discoveries (took place, have taken place) since the last centu­ry. 7. Last week they (analysed, analyse) crystal structure of those new materials by means of X-ray diffraction. 8. For many years considerable work (has been carried out, was carried out) to convert ethylene into motor fuel. 9. Many beautiful articles made of ceramics (provided, provides) man with tools even in ancient time.

14. Translate the following sentences paying attention to the word "provided":

1. These investigations provided new methods of detecting very minute quantities. 2. Provided the temperature is kept constant the volume of a given amount of gas is inversely proportional to its pressure and directly proportional to its absolute temperature. 3. The steel may be provided with the desired degree of hardness. 4. The laboratory is provided with gas and running water. 5. The expedition was provided with food for many days. 6. Provided the relative pressure of water is higher in the atmosphere (surroundings), vapour will condensate.

15. State parts of speech the words in bold type belong to:

1. Quartz was used in the form of large, nearly perfect crystals. 2. Quartz, silicates and aluminosilicates together with other minerals form a great amount of naturally occurring ceramic raw materials. 3. Among ceramic products, alumina in both its forms possesses the highest mechanical strength and hardness. 4. At first man could shape vessels of clay by hand. 5. The shape of this vessel was very strange. 6. Ceramic products are light in weight. 7. The light was shed on the use of new ceramic products. 8. The range of application of products made from clay is very wide. 9. The ceramic prod­ucts may range from bright lustrous ruby to dull clay.

16. Read these short texts and a) write out the words which belong to ceramic materials/products and their initial raw materials; b) title each text; c) answer the questions below.

I. Pottery, porcelain, brick and tile are all very similar in composition and method of manufacture, and with glass they provide the class of materials known as ceramics. These products are made from varying mixtures of clay, silica, and feldspar.

The very first of them are usually prepared from natural clays which already contain silica and feldspar. These natural clays are made into a workable mud with water and then fired in special ovens. As the temperature rises, water is first driven from the mixture, then various decomposition products are formed and above 1250° С the feldspar fuses and binds the other materials present.

Porcelain is made from a very fine white clay known as kaolin. Then very pure sands and feldspars are added. Very soft porcelain is obtained if one adds calcium phosphate to the mud.

II. Silicate materials include glass, porcelain, enamels and cement.

Ordinary glass is a mixture of silicates in the form of supercooled liquid. It is made by melting a mixture of sodium carbonate (or sodium sulphate), limestone and sand.

Ordinary glass contains about 10% sodium, 5% calcium, and 1% aluminum, the remainder is silicon and oxygen. It consists of an aluminosilicate tetrahedral framework, within which are embedded sodium ions and calcium ions.

III. Portland cement is an aluminosilicate powder which sets to a solid mass on treatment with water. Portland cement before treatment with water consists of a mixture of calcium silicates and calcium aluminate. When treated with water the calcium aluminate hydrolyzes and forms calcium hydroxide and aluminum hydroxide. These substances react further with the calcium silicates and produce calcium aluminosilicates in the form of crystals.

VI. With few exceptions, construction materials are solid materials or hardened into solid materials. Solid materials can be grouped into three fundamental types: ceramics, metals, and organics. The ceramic materials are rock or clay minerals, or are compounded from such minerals. Examples are: sand, limestone, glass, brick, cement, gypsum. These are materials which are dug from the earth's crust. Since they are extracted from the earth, they are relatively inexpensive as compared to metals or the organic materials. The ceramics have been used as building materials since ancient time.

1. What kind of materials are construction materials?

2. What types can solid materials be grouped into?

3. What are ceramic materials?

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